at91sam7x256 ATMEL Corporation, at91sam7x256 Datasheet - Page 12

• Manufacturer Part Number: at91sam7x256
• Description: Preliminary Summary
• Manufacturer: ATMEL Corporation

Adequate input supply decoupling is mandatory for VDDIN in order to improve startup stability
and reduce source voltage drop. The input decoupling capacitor should be placed close to the
chip. For example, two capacitors can be used in parallel: 100 nF NPO and 4.7 µF X7R.
5.4
Typical Powering Schematics
The AT91SAM7X512/256/128 supports a 3.3V single supply mode. The internal regulator input
connected to the 3.3V source and its output feeds VDDCORE and the VDDPLL.
Figure 5-1
shows the power schematics to be used for USB bus-powered systems.
Figure 5-1.
3.3V System Single Power Supply Schematic
VDDFLASH
Power Source
VDDIO
ranges
DC/DC Converter
from 4.5V (USB)
to 18V
VDDIN
Voltage
3.3V
Regulator
VDDOUT
VDDCORE
VDDPLL
AT91SAM7X512/256/128 Preliminary
12
6120ES–ATARM–08-Oct-07